header {
    width: 100%;
}

header img {
    width: 197px;
    height: 67px;
    margin: 15px 15px 0 0;
}

header .nav_big {
    height: 100px;
}

header .web p {
    width: 130px;
    color: rgb(136, 135, 137);
    font-size: 15px;
    text-align: center;
    line-height: 19px;
}

header .web {
    border-left: 2px solid rgb(168, 168, 168);
    height: 68px;
    margin-top: 16px;
    box-sizing: border-box;
    padding-top: 14px;
}

header .web span {
    font-size: 12px;
}

header .nav>li {
    float: left;
}

header .nav>li>a {
    color: rgb(121, 121, 121);
    display: inline-block;
    width: 128px;
    height: 100px;
    text-align: center;
    line-height: 100px;
}

header .nav>li>a:hover {
    background: #00ae69;
    color: white;
}

.nav_small {
    width: 128px;
    box-sizing: border-box;
    padding: 10px 5px;
    position: absolute;
    top: 100px;
    left: 0;
    display: none;
    background: white;
    z-index: 3;
}

.nav_small li a {
    display: block;
    width: 118px;
    height: 50px;
    text-align: center;
    line-height: 50px;
    background: white;
    color: rgb(121, 121, 121);
}

.nav_big {
    position: relative;
}

.nav_small li a:hover {
    background: #00ae68;
    color: white;
}

.nav_big1:hover .nav_small1 {
    display: block;
}

.nav_big2:hover .nav_small2 {
    display: block;
}

.nav_big3:hover .nav_small3 {
    display: block;
}

.nav_big4:hover .nav_small4 {
    display: block;
}


/* 大图片部分 */

#big_logo {
    width: 100%;
    height: 500px;
    background-image: url(../images/vynb.jpg);
    background-size: 100% 500px;
    position: relative;
}

#big_logo .p1 {
    font-family: 方正姚体;
    font-size: 30px;
    color: rgb(5, 45, 29);
    font-weight: bold;
    position: absolute;
    top: 134px;
    right: 296px;
    z-index: 1;
}

#big_logo .p2 {
    font-size: 12px;
    position: absolute;
    top: 178px;
    right: 280px;
    z-index: 1;
}


/* 小导航部分 */

#small_nav {
    width: 100%;
    height: 60px;
    background-color: rgba(0, 0, 0, 0.5);
    position: absolute;
    bottom: 0px;
}

#small_nav a {
    font-family: "Microsoft YaHei";
    font-size: 14px;
    color: rgb(255, 255, 255);
    line-height: 60px;
    display: inline-block;
    width: 294px;
    height: 60px;
    text-align: center;
    border-right: 1px solid white;
    margin-left: -5px;
}

#small_nav .small_nav1 {
    border-left: 1px solid white;
}

#small_nav a:hover {
    background: #00ae68;
}